APG 223 summarises a number of prudent lending practices for residential mortgages including the need for:

Credit risk assessment within the lender’s risk management framework

Sound loan origination criteria

Security valuation practices

Management of hardship loans

A robust stress-testing framework

“For customers who operate their investment property at a loss, where the income of the investment property does not exceed the costs, the related tax benefit will no longer be included in Bankwest's calculation for serviceability of the loan,” the spokesperson said.

The changes will impact all new applications involving an investment lending facility as well as any existing deals which may require a new serviceability calculation.